In foundation engineering and protective engineering for geological hazards, the anchor rod under-reaming technology is generally employed to support and reinforce the soil mass. During anchor rod reaming construction, the selection of an anchor rod reaming machine tool has an important influence on construction quality and cost.
For example, an anchor rod reaming machine tool provided by the prior art generally comprises a pressure rod, gears and reaming blades which are connected with a drill rod of an anchor rod drill rig. During use, firstly, drilling is performed by the drill rod of the anchor rod drill rig, and then the drill rod of the anchor rod drill rig is pressurized at the bottom of a hole to drive gear racks on the pressure rod for rectilinear movement, such that the gears rotate and hence the reaming blades expand or retract at the bottom of the hole to cut hole wall, thereby performing a reaming operation.
The inventors have found that the prior art at least has the following problem:
The anchor rod reaming machine tool provided by the prior art only can perform reaming at the bottom of the hole by means of blade cutting, which provides a poorer anti-pull-out property.